Bacterial infections are one cause of pericarditis . Since the introduction of antibiotics, bacterial pericarditis has become rare.

It most often occurs in men between the ages of 20 and 50, usually after some type of respiratory infection. It can also occur after skin or mouth infections that produce bacterial infection of the blood (bacteremia) and after heart surgery.

The bacterial infection causes the pericardium to become swollen and inflamed. Pain occurs as a result of the inflamed pericardium rubbing against the heart. Fluid may build up in the pericardial sac.